Supplied caption: 'Semi-submerged Ship S-3. The S-3 is a new semi-submerged ship concept for the design of an efficient, seaworthy, stable, multi-purpose ship which is practical from an engineering point of view over the size range from 100 tons to 15,000 tons. Makakai, Snoopy, CURV, DSRV. U. S. Naval Undersea Center, San Clemente Island , California'